Co2?

[Joemuz]

That is only true if you are injecting CO2. Surface agitation increases gas exchage. Molecules like CO2 and O2 move across the water/air barrier to reach equilibrium. For example, if there is a higher concentraton of CO2 in the air above the tank, because the CO2 in the water has been used up by plants, the CO2 will drive itself into the water. The CO2 will continue to go into the water, until the levels of CO2 in the air and water are equal. This is also applicable to O2 or if there is a higher concentration of CO2 in the water rather than the air. That is why CO2 injected tanks shouldn't have a lot of surface agitation, because it drives off the CO2, making it useless. Understand?

I think i do. But i dont know who to listen too? Sammie7 or nero?
I think sammie7's reply is more understandable as if there is no Co2 injection then an air pump should put more Co2 in to the water. (i think)
Thanks, Joemuz

 

[nero]

Hmmm, I see Sammies point, but what about the fact that there are fish in your aquarium respiring? That would lead to INCREASED co2, which in turn by using an airpump, you are driving off....

 

[Sammie7]

The fish add a neglible amount and if there was any decreased CO2 caused by the pump(which there wouldn't be) there the process would reverse once the molecules reached disequilibrium across the barrier. Like you said, fish would add a little CO2 to the system, but how fast do you think that would get used up? This is exactly why we have to inject CO2 because the amont produced by the fish isn't nearly enough.

 

[crazie.eddie]

Plants tanks that do not use CO2 and typically have lighting levels at less than 2 WPG (watts per gallon) are commonly known as low tech tanks. I have 2 low tech planted tanks and the plants are thriving well. They do grow, but slowly. The tanks are very easy to maintain, since I don't have to worry about fertilizers, CO2, constant trimming, etc. I let the water changes, decaying food, fish/shrimp waste provide the proper nutrients for the plants.

Sorry to hijack your thread Joe

By this do you mean that with my 29G tank (26G water level), overstocked fishwise, 60-70% substrate planted (with Tetra Complete underneath the playsand) and with 36W lights that I need no CO2, No Ferts and that the light, fish and food will supply all I need for a healthy planted with no algae tank?

I will reply to this, but if you have further questions, you should start your own thread with references and quotes from this thread.

Anyways, if you have easy maintenance, then yes. My 20 gallon long and my 29 gallon have such plants (java fern, Taiwan/Flame mosses, Sunset Hygro, etc) that I don't do much but just feed the fish/shrimp in there and perform water changes. I have less than 2wpg on both tanks and just use regular substrate.

 

[nero]

Ok, having thought about the airpump issue a bit more, I think the issue is academic anyway. Airpump or not, its not going to be adding any useful amount of co2.

 

[Sammie7]

Agreed. But it also helps to use logic as well as science .

 

[Joemuz]

Agreed. But it also helps to use logic as well as science .

I think i get it now. Thanks a lot everyone, Joemuz